Tankless water heaters... yeah or nay ?

[Evans, Marv]

Greg,
I'm having two Rinnai propane units installed in my the house I'm building. As somebody mentioned before, you need to pay attention to the amount of flow you need/want and the temperature rise vs. flow rate of the unit. I think I paid somewhere around $2.3K for both of mine. I'm hopeful they work out. My plumber knows what he is doing. You mentioned (I think) you needed to go with an electric unit. I thought of this since the rest of my appliances are electric. However, I discovered while researching them the electric units I would need drew 160 amps each (360 amps if both fire up). The power to the house in the beginning will be 200 amps, so it was propane for me. Check it out.

[911Rob]

Yeah.
Rennai, I pay $1600 over the HWT standard; so that's about $2600.

[look 171]

I know they are a lot more. Get a Takagi. they are well made and all are made in Japan. I talk with a rep and he claims that the Renni uses some Chinese made parts. I am sure they are good and up to standard. I have not heard one bad thing about Renni yet. I spend a whole day taking a class learning about their tankless heaters in Irvine. I have had my plumber do the install while I spec out what it needs. I have one of their largest unit at my house and are absolute happpy with it. I have a large tube with jets and and have run it with my muti head shower at the same time and have no problem with hot water. We are certify Renni installers too (no big deal, they spend a day telling you how and what they want you to do with their heaters), but my plumber has only installed something like 4 for our clients so far. I am thinking, why not install the best for my clients. Get them the porsche and not the Miata.

You might think about having 2 small units for your home, if not, you might want to run a recir. pump and a temp switch to stop the pump when necessary. Do not forget the expandsion tank.

I have not read through all the post, just came back from Alaska. Fire away if you have more questions.

Jeff

[CRH911S]

I had a Rennai installed last Dec and happy with its performance so far. It's set at 125f. The inbound flow is around 36f and it takes relatively little time to heat. Plenty of hot water for the jacuzzi tub and anything else. 10yr parts and labor warranty by HVAC company I have been using for years. Cost=3k. Sounds expensive but add that to the new G71 furnace I just installed and I'm happy with the results. It's a little too soon to tell but I expect savings of over 1k/yr compared to my earlier set up.
Now, why aren't you preheating your water? My dad had this wonderful set up on his home in Hesperia and he had unbelievably low gas bills. Water was preheated through roof system similar to solar panels.

[Steve W]

Noritz and Takagi are both good units - made in Japan. To work optimally, they need gas supplies larger than the standard line used for a regular water heater. They burn at a higher BTU rate to provide the instant and constant hot water supplied. This means a 1 1/4" supply line all the way from the meter, including a upsized meter, not the standard 1/2" or 3/4" line, otherwise the gas can't keep up with the flow, and the unit will continually choke off the water flow until the target temp is reached.

[look 171]

Steve,

Normally 3/4" is ok but I try to get it change it to 1" gas line just to be sure, depending how far away are you from the meter. Not having enough gas to the unit is the one mistake most plumbers make because many of them have not had a lot of experience with tankless heaters. They are use to insallation regular heaters. How are you doing with development? Are you still building and keeping busy?

Jeff

[creaturecat]

Rinnai on Natural gas. 1" gas line. Works fantastic.

[Oracle]

I have a Bosch electric under the sink in the garage that works perfectly.
Instant hot water on and no fluctuations unless you change the water flow (more water=less heat).
Bosch offers 5 year warranty, not bad eh?

[wild man]

Since I have gone this route (4 years ago), I guess I should chime in. Gas is not available where I live, so the unit I have is electric (as was the previous tanked unit that was there when I moved in). The unit is an EEMAX 10KW (or is it 9.5KW) size, and works great, as long a the bathroom has a low-flow (2gpm or lower) shower head installed. It only cost me $175 - comparable to a "standard" tanked unit. It is smaller in length and width than a shoe box, and only 1/3 the thickness. You do need to upgrade the wiring and circuit breaker that feed it to 40 amp capable. Considering how much others said they have paid to go tankless, I'm going to have to give it the BIG thumbs-up!

P.S. If you need higher flow, they make a thermostatically controlled unit ($200, if I recall correctly) that is installed after (downstream from) the first unit.

[Steve W]

Originally Posted by look 171

Steve,

Normally 3/4" is ok but I try to get it change it to 1" gas line just to be sure, depending how far away are you from the meter. Not having enough gas to the unit is the one mistake most plumbers make because many of them have not had a lot of experience with tankless heaters. They are use to insallation regular heaters. How are you doing with development? Are you still building and keeping busy?

Jeff

Everything has slowed down considerably as you know - I had anticipated the market to peak in 04 so I tried my best to position for it, but was surprised to see extend as far as it did. It was very obvious in 06 observing your suppliers, subs, and mortgage agents that the market had peaked and the downfall was occurring. I do not expect a bottoming until 2012, but till then I would keep my eye out for opportunity.

Regarding the tankless, I use Noritz exclusively, from the advice of my long trusted plumbing sub who builds out 500 tract homes/year. They work very well and you cannot tell any difference from the delivery or speed compared to a tanked water heater, except you don't run out of hot water. It typically runs about $1200-2000 in new construction, depending on the amount of the expensive stainless vent pipes you require. Mounting the unit outside normally reduces the cost as you can vent it right at the unit. I might also mention I have two gas tankless heaters running in parallel supply a 25 unit rental without issues. The space savings from the elimination of the tank and vent shafts, the significant weight reduction of not having 1000-1200 lbs load down your structure, and the gas savings is very significant!